Equivalent Units of Conversion Costs The Rolling Department of Blackrock Steel Company had 800 tons in beginning work in process inventory (20% complete). During the period, 12,700 tons were completed. The ending work in process inventory was 2,000 tons (30% complete). What are the total equivalent units for conversion costs? 8X units Feedback Check My Work Are you determining the equivalent units of materials added or of conversion of materials? When would materials typically be added in the process? When would conversion of these materials take place? Recall the definition of work in process.